Hi A Dark Side of Solar Power!!!

Hi A Dark Side of Solar Power!!!

The harshest criticism for fossil fuels has always been the horrible effect they have on the environment. Not only does retrieving the resource (coal, petroleum, natural gas) do irreparable damage to landscapes and ecosystems, but transporting it can be quite dangerous. And once the fuel has been spent, harmful byproducts clog the atmosphere and have far-reaching effects that scientists have only recently begun to quantify.

You know this, and I know this. And I know that you know that we all know this. This isn't going to be a recital of facts we know, ya know? But what about the negative environmental impacts our cultural shift to renewable energies, namely solar power, produce? There is a side to solar (PV) power that's rarely considered and not well understood.

Energy Payback Time (EPBT):

EPBT is the amount of time it takes a solar panel to collect the same value of energy that was expended in the panel's creation. It used to be that panels virtually never recaptured the amount of energy which was needed to create them, but that belief faded in the 1990s as the technology improved.

A significant amount of energy is spent producing, processing, and purifying materials for PV panels, as well as for the manufacture, transportation, and installation of the panel. The mathematical formula (.pdf) for determining the EPBT looks like this:

Rather than break down figures for areas with my limited text space, I'll just spoil the conclusion: the effectiveness of solar panels is severely affected by material efficiency and the location of the panel. In most of the United States, it takes almost two years before the panels begin to reduce emissions. At what latitude do solar panels stop making sense?

Environmental Waste:

Not surprisingly, China has been the leading manufacturer of PV panels worldwide by nearly fourfold. Despite this robust production rate, they're only second in PV power production (18,400 mW compared to Germany's 36k mW). What gives?

Frankly, China doesn't care about its environment and has little oversight on how companies dispose of industrial waste. And in consideration of the profit the industry is making, what regulations do exist are overlooked. U.S.-based PV panel manufacturers have a hard time disposing of toxic materials used in the production process. Chinese companies don't have the same difficulty, choosing to bury chemicals or flush them in public waterways. The result is a panel which was cheaper to produce and ship abroad.

Really, we're just burying the problem someplace else, hoping that a super-solution from future geniuses materializes in the meantime.

Wildlife Impacts:

The Ivanpah solar plant in utilizes 174,000 heliostats to reflect sunlight onto a centralized solar tower. The tower collects the sunlight, transfers it to heat, and boils water to begin the electricity production process. The plant is located in the Mojave Desert, away from population centers.

Human population centers, at least. While the imagery of a desert solar plant probably conjures images of dust and tumbleweeds, the area where the plant lives is much more lush than you might expect. When the plant was first announced, it incited considerable backlash because it was building on habitat that belonged to the endangered desert tortoise. The plant's construction was ultimately changed to help curtail its effects.

Now that the plant is up and running, an unforeseen consequence has occurred: an excessive number of bird deaths. Birds are lured to the area by insects or migration patterns, but once in the vicinity of the plant they're almost assured a hellish death. Estimates of up to 28,000 bird deaths a year have been attributed to the concentrated solar arrays, which blind and even ignite birds midflight. Officials are considering how to proceed with a megawatt and mega-money facility that may drive the extinction of entire species on its own.

The point isn't that solar power is harming our environment. Without a doubt, nearly any energy harvest strategy will conclude with negative environmental effects. But it shows that a long, long road of development must be traveled before our technology creates the sustainable utopia we envision. For now, we should probably maximize the efficiencies of the energy sources we have.

Hi Earth tunnel Air conditioning!.

Hi Earth tunnel Air conditioning!.

Earth tunnel Air conditioning system also known as passive air conditioning, is a wonder utilization of nature. It is also called as Earth tubes in Europe, Earth-air heat exchangers in North America, Earth tunnelling in India. These systems are known by several other names, including air-to-soil heat exchanger, earth channels, earth canals, earth-air tunnel systems, ground tube heat exchanger, subsoil heat exchangers, underground air pipes, and others.

Material;

Most systems are usually a network of pipes made of concrete, PVC, steel, rigid or semi-rigid plastic, plastic-coated metal pipes or plastic pipes coated with inner antimicrobial layers. These pipes are 100 – 600 mm (4 - 24 inches) in diameter and have a smooth inner surface. The diameter, layout and cleanliness of the piping is critical for the overall performance of the system.

Smaller diameter tubes require more energy to move the air and have less earth contact surface area. Larger tubes permit a slower airflow, which also yields more efficient energy transfer and permits much higher volumes to be transferred, permitting more air exchanges in a shorter time period.

Laying;

Soil temperature, at a depth of about 4.0 to 5.0m (12 - 15 feet), stays fairly constant throughout the year, and is approximately equal to the average annual ambient air temperature. Ground temperature becomes more stable with depth. The ground can, therefore, be used as a heat sink for cooling in the summer and as a heat source for heating in the winter.

The underground ambient earth temperature is typically 10 to 23 °C (50 -73 °F ) all year round in the temperate latitudes where most humans live. Daily and annual temperature fluctuations decreases with the increase in depth below the ground surface.

Daily temperature variations hardly affect the earth's temperature at a depth of more than one meter, while the seasonal variations of the ambient temperature are strongly dampened by the earth. The earth's temperature up to a depth of 6.0 to 8.0 m (18 – 24 feet) is influenced by the annual ambient temperature variations with a time delay of several months.

Avoid;

The piping system should avoid sharp 90-degree angles in the construction. Smooth wall tubes are more efficient in moving the air, they are less efficient in transferring energy. Two 45-degree bends produce less-turbulent, but more efficient air flow.

Types;

1. Closed loop system : In this system, same air is recirculated in the building. The air from inside the building is blown through a U-shaped loop of pipes which are 30.0 to 150.0 m (100 to 500 feet) in length. The air is moderated to near earth temperature before returning to be distributed via ductwork throughout the building. The closed loop system can be more effective than an open system, since it cools and re cools the same air.

2. Open system : In this system the outside air is drawn from a filtered air intake. The cooling tubes are typically 30.0 m (100 feet) long straight tubes drawn into the building. It is a process of exchanging the energy contained from outdoor ventilation. During the warmer seasons, the system pre-cools and dehumidifies, while humidifying and pre-heating in the cooler seasons. This system helps to improve the indoor air quality while reducing total HVAC equipment capacity.
   An open system combined with energy recovery ventilation can be nearly as efficient (80-95%) as a closed loop, and ensures that entering fresh air is filtered and tempered.
   
   
3. Combination system: This is a combination of both the above systems. This can be constructed with dampers that allow either closed or open operation, depending on fresh air ventilation requirements. Such a design, even in closed loop mode, could draw a quantity of fresh air when an air pressure drop is created. It is better to draw in filtered passive cooling tube air than unconditioned outside air.

Working;

A tunnel is dug 4m below ground level and network of pipes are laid. The length of the pipe is proportional to the area of the building that has to be air conditioned. One of the above system is used to circulate or recirculate the air. Fresh air which is drawn from inside or outside the building, is forced into these pipes which passes through the cooler or heater where the air is cooled or heated and it then pumped into the building. This method helps air to pass through an underground air tunnel. The air thus cooled or heated can be used directly for the conditioned space or indirectly with air conditioners or heat pumps.

The ambient air ventilated through this tunnel will get cooled in summer and warmed in winter. This method can be used for cooling in summer and heating in winter. This method can be used for either partial or full cooling and/or heating of air.

Removing hot air from building

The simple method called as Stack effect system connects the vertical ducts that project above the roof line of the building and works using the convection system of air by sucking out the stale air. The roof is fitted with a fan which takes away the hot air from the vertical pipes.

Maintaining moderate earth temperature

Sensible cooling can be aided by evaporative cooling. To reduce the underground temperature, the ground can be shaded using vegetation and can be wetted by sprinkling water. This water seeps through and dampens the tunnel walls. A slow drip watering system may improve thermal performance. Damp soil in contact with the cooling tube conducts heat more efficiently than dry soil.

Merits;

• better indoor air quality.
• 100% fresh air circulation in the premises.
• cost effective in both up-front and capital costs.
• reduces long-term operation and maintenance costs
• consumes 1/3 Rd less energy than conventional AC system.
• minimum temperature can be achieved during peak summer.

Demerits;

• performance of the system depends on location's latitude, altitude, ambient Earth temperature, climatic temperature, relative humidity extremes, solar radiation, water table, soil type, soil moisture content and the efficiency of the building's exterior envelope design.

• dry and low density soil with little or no ground shade will yield the least benefit.

• less effective in hot humid climates where the ambient temperature of the earth approaches human comfort temperature. The higher the ambient temperature of the earth, the less effective they are for cooling and dehumidification.

Environmental impact;

With reference to today's diminishing fossil fuel reserves, increasing electrical costs, air pollution and global warming, properly designed earth cooling tubes offer a sustainable alternative to reduce or eliminate the need for conventional compressor-based air conditioning systems. They also provide the added benefit of controlled, filtered, temperate fresh air intake, which is especially valuable in tight, well-weathered, efficient building envelopes.

Hi Visit Events Eye "Green Build."

Hi Events Eye "Green Build."

!!JOIN THE GREEN REVOLUTION IN THE BIG EASY!!

In 2014, we're joining together in New Orleans from Oct. 22-24 for Leadership Jazz. 

The music of the green movement is undeniable – its lyrics are engaging individuals across the world, its innovation is reviving our spirit and its passion is fueling the future. 

Together our unique ideas are improvising a melody that is leading a successful transformation of our building and communities. 

The Big Easy is the perfect setting to celebrate this global impact, while also embracing the essence of community, culture and soul. In 2013, USGBC turned 20, and we invite you to join the revolution as we build momentum and march into the next 20 years.

Hi Event Intro...,

Hi Top 10 countries for LEED!.

Hi Top 10 countries for LEED!.

Did your country make the top ten list?

LEED projects can be found in over 140 countries and territories around 

the world and on six out of seven continents — there are no LEED projects in Antarctica, but you never know what the future holds.

To provide a better view of LEED’s impact globally, we've ranked the top 10 countries for LEED outside of the U.S.. Looking at the gross square meters of certified space around the globe, we came up with the list below.

Click Here Or Image Above To Visit Leed Official Website!.

What’s changed over the last year?

Canada, China and India have always led the way for LEED projects and in the last year they certified a combined total of 13 million gross square meters.

The top ten countries together, represent 61 million gross square meters of LEED-certified space. That’s an increase of 41% from last year. 

Brazil, which ranks seventh for LEED-certified gross square meters of space and fourth for LEED-certified projects, recently certified two stadiums in preparation for the 2014 World Cup games. 

They have the largest number of certified stadiums and the only platinum certified stadiums outside the U.S.

Hi Artificial Cooling Tricky Topic for Climate Panel!.

Hi Artificial Cooling Tricky Topic for Climate Panel!.

BERLIN (AP) -- It's Plan B in the fight against climate change: cooling the planet by sucking heat-trapping CO2 from the air or reflecting sunlight back into space.

Called geoengineering, it's considered mad science by opponents.

Supporters say it would be foolish to ignore it, since plan A - slashing carbon emissions from fossil fuels - is moving so slowly.

The U.N.'s expert panel on climate change is under pressure from both sides this week as it considers whether geoengineering should be part of the tool-kit that governments use to keep global warming in check.

Russia, in particular, has been pushing the panel to place more emphasis on such techniques in a key document for policymakers being finalized in Berlin this week.

Drafts leaked before the conference only mentioned one of the options, removing CO2 from the air and storing it underground. Russia, a major oil and gas producer, said the Intergovernmental Panel on Climate Change should also mention solar radiation management, which could include everything from covering open surfaces with reflective materials or placing sun-mirrors in orbit around the Earth.

'It is expedient to give a short description of the approach and mention the major 'pro and contra',' Russia said in comments submitted to the IPCC and seen by The Associated Press.

But even advocates of studying geoengineering express doubts.

'Really at the present moment there is a high level of uncertainty surrounding all of these options,' said Steve Rayner, co-director of Oxford University's geoengineering program. Still, he said it's worth continuing to research geoengineering 'to get a better sense of whether there's any merit in pursuing these technologies further.'

After discussions among governments and scientists, a mention of geoengineering was added last year to the first of four summaries of the IPCC's authoritative assessment on climate change. They are now working on the third one, which deals specifically with fighting climate change.

The document is important because it will be used as scientific guidance for governments as they negotiate a new global climate pact, set to be adopted in 2015.

Some environmental activists watching the talks in Berlin want the Intergovernmental Panel on Climate Change to scratch references to geoengineering altogether. They worry that such technologies would be ineffective, possibly harmful and delay efforts to shift the world's energy system from oil and coal to low-carbon energy sources like wind and solar power.

'It seems like a dangerous gamble to hold up this technology that may not work,' said Jim Thomas, of the Canada-based ETC Group.

However, the IPCC's draft document says that unless emissions are cut much faster than currently projected, measures to scrub CO2 from the air will be have to be deployed to avoid potentially dangerous levels of warming.

The problem is those technologies don't exist yet or are in an experimental stage. 

- "No one knows whether they will be successful."

Ideas include spraying clouds with seawater to make them more reflective or pumping aerosols into the air to mimic the cooling effect from major volcanic eruptions.

Each is associated with unknown risks, including potentially shifting weather patterns or damaging the ozone layer that protects the Earth from ultraviolet sunrays.

One technology that is currently being tested at a small scale is called 'bioenergy with carbon capture and storage,' or BECCS. 

The idea is to grow crops that absorb CO2 from the atmosphere then burn them in a power station to generate energy. 

The resulting CO2 emissions are captured at the plant and then stored deep underground. The net effect of that process is that CO2 is removed from the air.

In a scientific report underlying the summary for policy-makers being discussed in Berlin and obtained by AP, the IPCC notes that BECCS could play a key role in curbing the buildup of CO2 in the atmosphere, which scientists say is the main reason for global warming. 

However, it would have to be deployed at a large scale, which would require major investments. 

There could also be negative impacts if food crops are replaced by bio-crops.

Right now the carbon removed through this technique is only a fraction of the 30 billion tons of CO2 emitted annually from the combustion of fossil fuels.

'BECCS faces large challenges in financing and currently no such plants have been built and tested at scale,' the IPCC says in the draft report.